Web Client with Response Latency Awareness

ABSTRACT

Methods and systems for handling web requests with latency awareness are described herein. A system may receive a web request from a web client, and determine, based on an exponential moving average of past response times, whether to allow the web request to be sent out to the server. Based on this determination, the system may send the web request to the server. The system may receive a response to the web request and update the exponential moving average based on the response time associated with the received response. The response may be forwarded back to the web client.

FIELD

Aspects described herein generally relate to computer networking, webrequests, and hardware and software related thereto. More specifically,one or more aspects described herein provide methods and systems forimproved web request handlings.

BACKGROUND

The World Wide Web (WWW) technology, built on the Hypertext TransferProtocol (HTTP), is one of the hallmarks of modern communications on theInternet. In accordance with the HTTP application layer protocol, aclient and a server may exchange request and response messages. Forexample. The client may submit an HTTP request message to the server,and the server may provide resources (e.g., Hypertext Markup Language(HTML) files, photos, videos, etc.) by returning a response message tothe client.

However, various adverse network conditions may hinder or prevent theclient from receiving a response from the server after sending arequest. This not only can decrease the efficiency of communication butcan greatly affect the user experience in a negative way as well.Notably, the user may find it unbearable having to wait idly for aresponse for a long time and may actually prefer receiving immediatefeedback even if that meant being served with an error message.Furthermore, the frustrated user may continue to issue multiplerequests, which may overwhelm the server thereby further exacerbatingthe situation. Thus, there exists a need to better manage web requestsand responses to improve user experience when the network conditiondeteriorates.

SUMMARY

The following presents a simplified summary of various aspects describedherein. This summary is not an extensive overview, and is not intendedto identify required or critical elements or to delineate the scope ofthe claims. The following summary merely presents some concepts in asimplified form as an introductory prelude to the more detaileddescription provided below.

To overcome limitations in the prior art described above, and toovercome other limitations that will be apparent upon reading andunderstanding the present specification, aspects described herein aredirected towards improved management of web requests and responses.

In some embodiments, a system may receive, from a web client, a firstweb request. The system may determine, based on an exponential movingaverage of a plurality of past response times, whether to allow thefirst web request. The system may send, based on the determination, thefirst web request to a server. The system may receive, from the server,a response to the first web request. The system may determine a responsetime associated with the response. The system may determine, based onthe response time and the exponential moving average of the plurality ofpast response times, an updated exponential moving average. The systemmay send the response to the web client.

The first web request may be a hypertext transfer protocol (HTTP)request.

Sending the first web request may include initiating a timer, anddetermining the response time may include calculating the response timebased on the timer, and recording the response time.

Determining the updated exponential moving average may be based on theformula, A_(U)=(R−A_(C))×C+A_(C), where A_(U) is the updated exponentialmoving average, R is the response time, A_(C) is the exponential movingaverage of the plurality of past response times, and C is a smoothingconstant.

The smoothing constant may be determined based on the formula,C=2÷(N+1), where N is a weight value.

The first web request may include an indication of a category associatedwith the first web request. The plurality of past response times may beassociated with the category.

The system may receive, from the web client and after receiving thefirst web request, a second web request. Based on the updatedexponential moving average, the system may determine to disallow thesecond web request from being sent to the server. The system may send anerror response to the web client.

The error response may be hypertext transfer protocol (HTTP) responsestatus code indicating too many requests.

Determining whether to allow the first web request may include:determining to allow the first web request based on the formula,A_(C)+(A_(C)×C)>T, being satisfied, where A_(C) is the exponentialmoving average of the plurality of past response times, C is a smoothingconstant, and T is a timeout value; and/or determining to disallow thefirst web request based on the formula being not satisfied.

Determining whether to allow the first web request may includedetermining, among a plurality of exponential moving averages associatedwith respective categories, the exponential moving average associatedwith the category.

These and additional aspects will be appreciated with the benefit of thedisclosures discussed in further detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of aspects described herein and theadvantages thereof may be acquired by referring to the followingdescription in consideration of the accompanying drawings, in which likereference numbers indicate like features, and wherein:

FIG. 1 depicts an illustrative computer system architecture that may beused in accordance with one or more illustrative aspects describedherein.

FIG. 2 depicts an illustrative remote-access system architecture thatmay be used in accordance with one or more illustrative aspectsdescribed herein.

FIG. 3 depicts an illustrative virtualized system architecture that maybe used in accordance with one or more illustrative aspects describedherein.

FIG. 4 depicts an illustrative cloud-based system architecture that maybe used in accordance with one or more illustrative aspects describedherein.

FIG. 5 is a block diagram of an example system, in which a resourcemanagement service may manage and streamline access by a client toresource feeds and/or software-as-a-service (SaaS) applications.

FIG. 6A is a block diagram showing an example implementation, in whichvarious resource management services as well as a gateway service arelocated within a cloud computing environment.

FIG. 6B is a block diagram, in which the available resources arerepresented by a sin

FIG. 7 depicts a block diagram illustrating an example system for makingand responding to web requests.

FIG. 8 depicts a block diagram illustrating an example flow of managingweb requests with respect to an example system.

FIG. 9 depicts a table with illustrative web request response times andother related data.

FIG. 10 depicts a graph with illustrative web request response times andother related data.

FIG. 11 depicts example category types for managing web requests.

FIG. 12 depicts an outbound flow algorithm of an illustrative method forhandling web requests.

FIG. 13 depicts an inbound flow algorithm of an illustrative method forhandling web responses.

DETAILED DESCRIPTION

In the following description of the various embodiments, reference ismade to the accompanying drawings identified above and which form a parthereof, and in which is shown by way of illustration various embodimentsin which aspects described herein may be practiced. It is to beunderstood that other embodiments may be utilized and structural andfunctional modifications may be made without departing from the scopedescribed herein. Various aspects are capable of other embodiments andof being practiced or being carried out in various different ways.

As a general introduction to the subject matter described in more detailbelow, aspects described herein are directed towards management of webrequests and responses, and throttling requests based on the exponentialmoving average of past response times. The exponential moving averagemay be constantly updated based on latest response times and subsequentweb requests may be throttled when the exponential moving averagebecomes too high. Additionally, if the response time exceeds apredetermined timeout value, then the timeout value may be figured intocalculating the next exponential moving average.

It is to be understood that the phraseology and terminology used hereinare for the purpose of description and should not be regarded aslimiting. Rather, the phrases and terms used herein are to be giventheir broadest interpretation and meaning. The use of “including” and“comprising” and variations thereof is meant to encompass the itemslisted thereafter and equivalents thereof as well as additional itemsand equivalents thereof. The use of the terms “connected,” “coupled,”“engaged” and similar terms, is meant to include both direct andindirect connecting, coupling, and engaging.

Computing Architecture

Computer software, hardware, and networks may be utilized in a varietyof different system environments, including standalone, networked,remote-access (also known as remote desktop), virtualized, and/orcloud-based environments, among others. FIG. 1 illustrates one exampleof a system architecture and data processing device that may be used toimplement one or more illustrative aspects described herein in astandalone and/or networked environment. Various network nodes 103, 105,107, and 109 may be interconnected via a wide area network (WAN) 101,such as the Internet. Other networks may also or alternatively be used,including private intranets, corporate networks, local area networks(LAN), metropolitan area networks (MAN), wireless networks, personalnetworks (PAN), and the like. Network 101 is for illustration purposesand may be replaced with fewer or additional computer networks. A localarea network 133 may have one or more of any known LAN topology and mayuse one or more of a variety of different protocols, such as Ethernet.Devices 103, 105, 107, and 109 and other devices (not shown) may beconnected to one or more of the networks via twisted pair wires, coaxialcable, fiber optics, radio waves, or other communication media.

The term “network” as used herein and depicted in the drawings refersnot only to systems in which remote storage devices are coupled togethervia one or more communication paths, but also to stand-alone devicesthat may be coupled, from time to time, to such systems that havestorage capability. Consequently, the term “network” includes not only a“physical network” but also a “content network,” which is comprised ofthe data-attributable to a single entity-which resides across allphysical networks.

The components may include data server 103, web server 105, and clientcomputers 107, 109. Data server 103 provides overall access, control andadministration of databases and control software for performing one ormore illustrative aspects describe herein. Data server 103 may beconnected to web server 105 through which users interact with and obtaindata as requested. Alternatively, data server 103 may act as a webserver itself and be directly connected to the Internet. Data server 103may be connected to web server 105 through the local area network 133,the wide area network 101 (e.g., the Internet), via direct or indirectconnection, or via some other network. Users may interact with the dataserver 103 using remote computers 107, 109, e.g., using a web browser toconnect to the data server 103 via one or more externally exposed websites hosted by web server 105. Client computers 107, 109 may be used inconcert with data server 103 to access data stored therein, or may beused for other purposes. For example, from client device 107 a user mayaccess web server 105 using an Internet browser, as is known in the art,or by executing a software application that communicates with web server105 and/or data server 103 over a computer network (such as theInternet).

Servers and applications may be combined on the same physical machines,and retain separate virtual or logical addresses, or may reside onseparate physical machines. FIG. 1 illustrates just one example of anetwork architecture that may be used, and those of skill in the artwill appreciate that the specific network architecture and dataprocessing devices used may vary, and are secondary to the functionalitythat they provide, as further described herein. For example, servicesprovided by web server 105 and data server 103 may be combined on asingle server.

Each component 103, 105, 107, 109 may be any type of known computer,server, or data processing device. Data server 103, e.g., may include aprocessor 111 controlling overall operation of the data server 103. Dataserver 103 may further include random access memory (RAM) 113, read onlymemory (ROM) 115, network interface 117, input/output interfaces 119(e.g., keyboard, mouse, display, printer, etc.), and memory 121.Input/output (I/O) 119 may include a variety of interface units anddrives for reading, writing, displaying, and/or printing data or files.Memory 121 may further store operating system software 123 forcontrolling overall operation of the data processing device 103, controllogic 125 for instructing data server 103 to perform aspects describedherein, and other application software 127 providing secondary, support,and/or other functionality which may or might not be used in conjunctionwith aspects described herein. The control logic 125 may also bereferred to herein as the data server software 125. Functionality of thedata server software 125 may refer to operations or decisions madeautomatically based on rules coded into the control logic 125, mademanually by a user providing input into the system, and/or a combinationof automatic processing based on user input (e.g., queries, dataupdates, etc.).

Memory 121 may also store data used in performance of one or moreaspects described herein, including a first database 129 and a seconddatabase 131. In some embodiments, the first database 129 may includethe second database 131 (e.g., as a separate table, report, etc.). Thatis, the information can be stored in a single database, or separatedinto different logical, virtual, or physical databases, depending onsystem design. Devices 105, 107, and 109 may have similar or differentarchitecture as described with respect to device 103. Those of skill inthe art will appreciate that the functionality of data processing device103 (or device 105, 107, or 109) as described herein may be spreadacross multiple data processing devices, for example, to distributeprocessing load across multiple computers, to segregate transactionsbased on geographic location, user access level, quality of service(QoS), etc.

One or more aspects may be embodied in computer-usable or readable dataand/or computer-executable instructions, such as in one or more programmodules, executed by one or more computers or other devices as describedherein. Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types when executed by a processor ina computer or other device. The modules may be written in a source codeprogramming language that is subsequently compiled for execution, or maybe written in a scripting language such as (but not limited to)HyperText Markup Language (HTML) or Extensible Markup Language (XML).The computer executable instructions may be stored on a computerreadable medium such as a nonvolatile storage device. Any suitablecomputer readable storage media may be utilized, including hard disks,CD-ROMs, optical storage devices, magnetic storage devices, solid statestorage devices, and/or any combination thereof. In addition, varioustransmission (non-storage) media representing data or events asdescribed herein may be transferred between a source and a destinationin the form of electromagnetic waves traveling through signal-conductingmedia such as metal wires, optical fibers, and/or wireless transmissionmedia (e.g., air and/or space). Various aspects described herein may beembodied as a method, a data processing system, or a computer programproduct. Therefore, various functionalities may be embodied in whole orin part in software, firmware, and/or hardware or hardware equivalentssuch as integrated circuits, field programmable gate arrays (FPGA), andthe like. Particular data structures may be used to more effectivelyimplement one or more aspects described herein, and such data structuresare contemplated within the scope of computer executable instructionsand computer-usable data described herein.

With further reference to FIG. 2, one or more aspects described hereinmay be implemented in a remote-access environment. FIG. 2 depicts anexample system architecture including a computing device 201 in anillustrative computing environment 200 that may be used according to oneor more illustrative aspects described herein. Computing device 201 maybe used as a server 206 a in a single-server or multi-server desktopvirtualization system (e.g., a remote access or cloud system) and can beconfigured to provide virtual machines for client access devices. Thecomputing device 201 may have a processor 203 for controlling overalloperation of the device 201 and its associated components, including RAM205, ROM 207, Input/Output (I/O) module 209, and memory 215.

I/O module 209 may include a mouse, keypad, touch screen, scanner,optical reader, and/or stylus (or other input device(s)) through which auser of computing device 201 may provide input, and may also include oneor more of a speaker for providing audio output and one or more of avideo display device for providing textual, audiovisual, and/orgraphical output. Software may be stored within memory 215 and/or otherstorage to provide instructions to processor 203 for configuringcomputing device 201 into a special purpose computing device in order toperform various functions as described herein. For example, memory 215may store software used by the computing device 201, such as anoperating system 217, application programs 219, and an associateddatabase 221.

Computing device 201 may operate in a networked environment supportingconnections to one or more remote computers, such as terminals 240 (alsoreferred to as client devices and/or client machines). The terminals 240may be personal computers, mobile devices, laptop computers, tablets, orservers that include many or all of the elements described above withrespect to the computing device 103 or 201. The network connectionsdepicted in FIG. 2 include a local area network (LAN) 225 and a widearea network (WAN) 229, but may also include other networks. When usedin a LAN networking environment, computing device 201 may be connectedto the LAN 225 through a network interface or adapter 223. When used ina WAN networking environment, computing device 201 may include a modemor other wide area network interface 227 for establishing communicationsover the WAN 229, such as computer network 230 (e.g., the Internet). Itwill be appreciated that the network connections shown are illustrativeand other means of establishing a communications link between thecomputers may be used. Computing device 201 and/or terminals 240 mayalso be mobile terminals (e.g., mobile phones, smartphones, personaldigital assistants (PDAs), notebooks, etc.) including various othercomponents, such as a battery, speaker, and antennas (not shown).

Aspects described herein may also be operational with numerous othergeneral purpose or special purpose computing system environments orconfigurations. Examples of other computing systems, environments,and/or configurations that may be suitable for use with aspectsdescribed herein include, but are not limited to, personal computers,server computers, hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, set top boxes, programmable consumerelectronics, network personal computers (PCs), minicomputers, mainframecomputers, distributed computing environments that include any of theabove systems or devices, and the like.

As shown in FIG. 2, one or more client devices 240 may be incommunication with one or more servers 206 a-206 n (generally referredto herein as “server(s) 206”). In one embodiment, the computingenvironment 200 may include a network appliance installed between theserver(s) 206 and client machine(s) 240. The network appliance maymanage client/server connections, and in some cases can load balanceclient connections amongst a plurality of backend servers 206.

The client machine(s) 240 may in some embodiments be referred to as asingle client machine 240 or a single group of client machines 240,while server(s) 206 may be referred to as a single server 206 or asingle group of servers 206. In one embodiment a single client machine240 communicates with more than one server 206, while in anotherembodiment a single server 206 communicates with more than one clientmachine 240. In yet another embodiment, a single client machine 240communicates with a single server 206.

A client machine 240 can, in some embodiments, be referenced by any oneof the following non-exhaustive terms: client machine(s); client(s);client computer(s); client device(s); client computing device(s); localmachine; remote machine; client node(s); endpoint(s); or endpointnode(s). The server 206, in some embodiments, may be referenced by anyone of the following non-exhaustive terms: server(s), local machine;remote machine; server farm(s), or host computing device(s).

In one embodiment, the client machine 240 may be a virtual machine. Thevirtual machine may be any virtual machine, while in some embodimentsthe virtual machine may be any virtual machine managed by a Type 1 orType 2 hypervisor, for example, a hypervisor developed by CitrixSystems, IBM, VMware, or any other hypervisor. In some aspects, thevirtual machine may be managed by a hypervisor, while in other aspectsthe virtual machine may be managed by a hypervisor executing on a server206 or a hypervisor executing on a client 240.

Some embodiments include a client device 240 that displays applicationoutput generated by an application remotely executing on a server 206 orother remotely located machine. In these embodiments, the client device240 may execute a virtual machine receiver program or application todisplay the output in an application window, a browser, or other outputwindow. In one example, the application is a desktop, while in otherexamples the application is an application that generates or presents adesktop. A desktop may include a graphical shell providing a userinterface for an instance of an operating system in which local and/orremote applications can be integrated. Applications, as used herein, areprograms that execute after an instance of an operating system (and,optionally, also the desktop) has been loaded.

The server 206, in some embodiments, uses a remote presentation protocolor other program to send data to a thin-client or remote-displayapplication executing on the client to present display output generatedby an application executing on the server 206. The thin-client orremote-display protocol can be any one of the following non-exhaustivelist of protocols: the Independent Computing Architecture (ICA) protocoldeveloped by Citrix Systems, Inc. of Ft. Lauderdale, Fla.; or the RemoteDesktop Protocol (RDP) manufactured by the Microsoft Corporation ofRedmond, Wash.

A remote computing environment may include more than one server 206a-206 n such that the servers 206 a-206 n are logically grouped togetherinto a server farm 206, for example, in a cloud computing environment.The server farm 206 may include servers 206 that are geographicallydispersed while logically grouped together, or servers 206 that arelocated proximate to each other while logically grouped together.Geographically dispersed servers 206 a-206 n within a server farm 206can, in some embodiments, communicate using a WAN (wide), MAN(metropolitan), or LAN (local), where different geographic regions canbe characterized as: different continents; different regions of acontinent; different countries; different states; different cities;different campuses; different rooms; or any combination of the precedinggeographical locations. In some embodiments the server farm 206 may beadministered as a single entity, while in other embodiments the serverfarm 206 can include multiple server farms.

In some embodiments, a server farm may include servers 206 that executea substantially similar type of operating system platform (e.g.,WINDOWS, UNIX, LINUX, iOS, ANDROID, etc.) In other embodiments, serverfarm 206 may include a first group of one or more servers that execute afirst type of operating system platform, and a second group of one ormore servers that execute a second type of operating system platform.

Server 206 may be configured as any type of server, as needed, e.g., afile server, an application server, a web server, a proxy server, anappliance, a network appliance, a gateway, an application gateway, agateway server, a virtualization server, a deployment server, a SecureSockets Layer (SSL) VPN server, a firewall, a web server, an applicationserver or as a master application server, a server executing an activedirectory, or a server executing an application acceleration programthat provides firewall functionality, application functionality, or loadbalancing functionality. Other server types may also be used.

Some embodiments include a first server 206 a that receives requestsfrom a client machine 240, forwards the request to a second server 206 b(not shown), and responds to the request generated by the client machine240 with a response from the second server 206 b (not shown.) Firstserver 206 a may acquire an enumeration of applications available to theclient machine 240 as well as address information associated with anapplication server 206 hosting an application identified within theenumeration of applications. First server 206 a can then present aresponse to the client's request using a web interface, and communicatedirectly with the client 240 to provide the client 240 with access to anidentified application. One or more clients 240 and/or one or moreservers 206 may transmit data over network 230, e.g., network 101.

FIG. 3 shows a high-level architecture of an illustrative desktopvirtualization system. As shown, the desktop virtualization system maybe single-server or multi-server system, or cloud system, including atleast one virtualization server 301 configured to provide virtualdesktops and/or virtual applications to one or more client accessdevices 240. As used herein, a desktop refers to a graphical environmentor space in which one or more applications may be hosted and/orexecuted. A desktop may include a graphical shell providing a userinterface for an instance of an operating system in which local and/orremote applications can be integrated. Applications may include programsthat execute after an instance of an operating system (and, optionally,also the desktop) has been loaded. Each instance of the operating systemmay be physical (e.g., one operating system per device) or virtual(e.g., many instances of an OS running on a single device). Eachapplication may be executed on a local device, or executed on a remotelylocated device (e.g., remoted).

A computer device 301 may be configured as a virtualization server in avirtualization environment, for example, a single-server, multi-server,or cloud computing environment. Virtualization server 301 illustrated inFIG. 3 can be deployed as and/or implemented by one or more embodimentsof the server 206 illustrated in FIG. 2 or by other known computingdevices. Included in virtualization server 301 is a hardware layer thatcan include one or more physical disks 304, one or more physical devices306, one or more physical processors 308, and one or more physicalmemories 316. In some embodiments, firmware 312 can be stored within amemory element in the physical memory 316 and can be executed by one ormore of the physical processors 308. Virtualization server 301 mayfurther include an operating system 314 that may be stored in a memoryelement in the physical memory 316 and executed by one or more of thephysical processors 308. Still further, a hypervisor 302 may be storedin a memory element in the physical memory 316 and can be executed byone or more of the physical processors 308.

Executing on one or more of the physical processors 308 may be one ormore virtual machines 332A-C (generally 332). Each virtual machine 332may have a virtual disk 326A-C and a virtual processor 328A-C. In someembodiments, a first virtual machine 332A may execute, using a virtualprocessor 328A, a control program 320 that includes a tools stack 324.Control program 320 may be referred to as a control virtual machine,Dom0, Domain 0, or other virtual machine used for system administrationand/or control. In some embodiments, one or more virtual machines 332B-Ccan execute, using a virtual processor 328B-C, a guest operating system330A-B.

Virtualization server 301 may include a hardware layer 310 with one ormore pieces of hardware that communicate with the virtualization server301. In some embodiments, the hardware layer 310 can include one or morephysical disks 304, one or more physical devices 306, one or morephysical processors 308, and one or more physical memory 316. Physicalcomponents 304, 306, 308, and 316 may include, for example, any of thecomponents described above. Physical devices 306 may include, forexample, a network interface card, a video card, a keyboard, a mouse, aninput device, a monitor, a display device, speakers, an optical drive, astorage device, a universal serial bus connection, a printer, a scanner,a network element (e.g., router, firewall, network address translator,load balancer, virtual private network (VPN) gateway, Dynamic HostConfiguration Protocol (DHCP) router, etc.), or any device connected toor communicating with virtualization server 301. Physical memory 316 inthe hardware layer 310 may include any type of memory. Physical memory316 may store data, and in some embodiments may store one or moreprograms, or set of executable instructions. FIG. 3 illustrates anembodiment where firmware 312 is stored within the physical memory 316of virtualization server 301. Programs or executable instructions storedin the physical memory 316 can be executed by the one or more processors308 of virtualization server 301.

Virtualization server 301 may also include a hypervisor 302. In someembodiments, hypervisor 302 may be a program executed by processors 308on virtualization server 301 to create and manage any number of virtualmachines 332. Hypervisor 302 may be referred to as a virtual machinemonitor, or platform virtualization software. In some embodiments,hypervisor 302 can be any combination of executable instructions andhardware that monitors virtual machines executing on a computingmachine. Hypervisor 302 may be Type 2 hypervisor, where the hypervisorexecutes within an operating system 314 executing on the virtualizationserver 301. Virtual machines may then execute at a level above thehypervisor 302. In some embodiments, the Type 2 hypervisor may executewithin the context of a user's operating system such that the Type 2hypervisor interacts with the user's operating system. In otherembodiments, one or more virtualization servers 301 in a virtualizationenvironment may instead include a Type 1 hypervisor (not shown). A Type1 hypervisor may execute on the virtualization server 301 by directlyaccessing the hardware and resources within the hardware layer 310. Thatis, while a Type 2 hypervisor 302 accesses system resources through ahost operating system 314, as shown, a Type 1 hypervisor may directlyaccess all system resources without the host operating system 314. AType 1 hypervisor may execute directly on one or more physicalprocessors 308 of virtualization server 301, and may include programdata stored in the physical memory 316.

Hypervisor 302, in some embodiments, can provide virtual resources tooperating systems 330 or control programs 320 executing on virtualmachines 332 in any manner that simulates the operating systems 330 orcontrol programs 320 having direct access to system resources. Systemresources can include, but are not limited to, physical devices 306,physical disks 304, physical processors 308, physical memory 316, andany other component included in hardware layer 310 of the virtualizationserver 301. Hypervisor 302 may be used to emulate virtual hardware,partition physical hardware, virtualize physical hardware, and/orexecute virtual machines that provide access to computing environments.In still other embodiments, hypervisor 302 may control processorscheduling and memory partitioning for a virtual machine 332 executingon virtualization server 301. Hypervisor 302 may include thosemanufactured by VMWare, Inc., of Palo Alto, Calif.; HyperV,VirtualServer or virtual PC hypervisors provided by Microsoft, orothers. In some embodiments, virtualization server 301 may execute ahypervisor 302 that creates a virtual machine platform on which guestoperating systems may execute. In these embodiments, the virtualizationserver 301 may be referred to as a host server. An example of such avirtualization server is the Citrix Hypervisor provided by CitrixSystems, Inc., of Fort Lauderdale, Fla.

Hypervisor 302 may create one or more virtual machines 332B-C (generally332) in which guest operating systems 330 execute. In some embodiments,hypervisor 302 may load a virtual machine image to create a virtualmachine 332. In other embodiments, the hypervisor 302 may execute aguest operating system 330 within virtual machine 332. In still otherembodiments, virtual machine 332 may execute guest operating system 330.

In addition to creating virtual machines 332, hypervisor 302 may controlthe execution of at least one virtual machine 332. In other embodiments,hypervisor 302 may present at least one virtual machine 332 with anabstraction of at least one hardware resource provided by thevirtualization server 301 (e.g., any hardware resource available withinthe hardware layer 310). In other embodiments, hypervisor 302 maycontrol the manner in which virtual machines 332 access physicalprocessors 308 available in virtualization server 301. Controllingaccess to physical processors 308 may include determining whether avirtual machine 332 should have access to a processor 308, and howphysical processor capabilities are presented to the virtual machine332.

As shown in FIG. 3, virtualization server 301 may host or execute one ormore virtual machines 332. A virtual machine 332 is a set of executableinstructions that, when executed by a processor 308, may imitate theoperation of a physical computer such that the virtual machine 332 canexecute programs and processes much like a physical computing device.While FIG. 3 illustrates an embodiment where a virtualization server 301hosts three virtual machines 332, in other embodiments virtualizationserver 301 can host any number of virtual machines 332. Hypervisor 302,in some embodiments, may provide each virtual machine 332 with a uniquevirtual view of the physical hardware, memory, processor, and othersystem resources available to that virtual machine 332. In someembodiments, the unique virtual view can be based on one or more ofvirtual machine permissions, application of a policy engine to one ormore virtual machine identifiers, a user accessing a virtual machine,the applications executing on a virtual machine, networks accessed by avirtual machine, or any other desired criteria. For instance, hypervisor302 may create one or more unsecure virtual machines 332 and one or moresecure virtual machines 332. Unsecure virtual machines 332 may beprevented from accessing resources, hardware, memory locations, andprograms that secure virtual machines 332 may be permitted to access. Inother embodiments, hypervisor 302 may provide each virtual machine 332with a substantially similar virtual view of the physical hardware,memory, processor, and other system resources available to the virtualmachines 332.

Each virtual machine 332 may include a virtual disk 326A-C (generally326) and a virtual processor 328A-C (generally 328.) The virtual disk326, in some embodiments, is a virtualized view of one or more physicaldisks 304 of the virtualization server 301, or a portion of one or morephysical disks 304 of the virtualization server 301. The virtualizedview of the physical disks 304 can be generated, provided, and managedby the hypervisor 302. In some embodiments, hypervisor 302 provides eachvirtual machine 332 with a unique view of the physical disks 304. Thus,in these embodiments, the particular virtual disk 326 included in eachvirtual machine 332 can be unique when compared with the other virtualdisks 326.

A virtual processor 328 can be a virtualized view of one or morephysical processors 308 of the virtualization server 301. In someembodiments, the virtualized view of the physical processors 308 can begenerated, provided, and managed by hypervisor 302. In some embodiments,virtual processor 328 has substantially all of the same characteristicsof at least one physical processor 308. In other embodiments, virtualprocessor 308 provides a modified view of physical processors 308 suchthat at least some of the characteristics of the virtual processor 328are different than the characteristics of the corresponding physicalprocessor 308.

With further reference to FIG. 4, some aspects described herein may beimplemented in a cloud-based environment. FIG. 4 illustrates an exampleof a cloud computing environment (or cloud system) 400. As seen in FIG.4, client computers 411-414 may communicate with a cloud managementserver 410 to access the computing resources (e.g., host servers 403a-403 b (generally referred herein as “host servers 403”), storageresources 404 a-404 b (generally referred herein as “storage resources404”), and network elements 405 a-405 b (generally referred herein as“network resources 405”)) of the cloud system.

Management server 410 may be implemented on one or more physicalservers. The management server 410 may run, for example, Citrix Cloud byCitrix Systems, Inc. of Ft. Lauderdale, Fla., or OPENSTACK, amongothers. Management server 410 may manage various computing resources,including cloud hardware and software resources, for example, hostcomputers 403, data storage devices 404, and networking devices 405. Thecloud hardware and software resources may include private and/or publiccomponents. For example, a cloud may be configured as a private cloud tobe used by one or more particular customers or client computers 411-414and/or over a private network. In other embodiments, public clouds orhybrid public-private clouds may be used by other customers over an openor hybrid networks.

Management server 410 may be configured to provide user interfacesthrough which cloud operators and cloud customers may interact with thecloud system 400. For example, the management server 410 may provide aset of application programming interfaces (APIs) and/or one or morecloud operator console applications (e.g., web-based or standaloneapplications) with user interfaces to allow cloud operators to managethe cloud resources, configure the virtualization layer, manage customeraccounts, and perform other cloud administration tasks. The managementserver 410 also may include a set of APIs and/or one or more customerconsole applications with user interfaces configured to receive cloudcomputing requests from end users via client computers 411-414, forexample, requests to create, modify, or destroy virtual machines withinthe cloud. Client computers 411-414 may connect to management server 410via the Internet or some other communication network, and may requestaccess to one or more of the computing resources managed by managementserver 410. In response to client requests, the management server 410may include a resource manager configured to select and provisionphysical resources in the hardware layer of the cloud system based onthe client requests. For example, the management server 410 andadditional components of the cloud system may be configured toprovision, create, and manage virtual machines and their operatingenvironments (e.g., hypervisors, storage resources, services offered bythe network elements, etc.) for customers at client computers 411-414,over a network (e.g., the Internet), providing customers withcomputational resources, data storage services, networking capabilities,and computer platform and application support. Cloud systems also may beconfigured to provide various specific services, including securitysystems, development environments, user interfaces, and the like.

Certain clients 411-414 may be related, for example, to different clientcomputers creating virtual machines on behalf of the same end user, ordifferent users affiliated with the same company or organization. Inother examples, certain clients 411-414 may be unrelated, such as usersaffiliated with different companies or organizations. For unrelatedclients, information on the virtual machines or storage of any one usermay be hidden from other users.

Referring now to the physical hardware layer of a cloud computingenvironment, availability zones 401-402 (or zones) may refer to acollocated set of physical computing resources. Zones may begeographically separated from other zones in the overall cloud ofcomputing resources. For example, zone 401 may be a first clouddatacenter located in California, and zone 402 may be a second clouddatacenter located in Florida. Management server 410 may be located atone of the availability zones, or at a separate location. Each zone mayinclude an internal network that interfaces with devices that areoutside of the zone, such as the management server 410, through agateway. End users of the cloud (e.g., clients 411-414) might or mightnot be aware of the distinctions between zones. For example, an end usermay request the creation of a virtual machine having a specified amountof memory, processing power, and network capabilities. The managementserver 410 may respond to the user's request and may allocate theresources to create the virtual machine without the user knowing whetherthe virtual machine was created using resources from zone 401 or zone402. In other examples, the cloud system may allow end users to requestthat virtual machines (or other cloud resources) are allocated in aspecific zone or on specific resources 403-405 within a zone.

In this example, each zone 401-402 may include an arrangement of variousphysical hardware components (or computing resources) 403-405, forexample, physical hosting resources (or processing resources), physicalnetwork resources, physical storage resources, switches, and additionalhardware resources that may be used to provide cloud computing servicesto customers. The physical hosting resources in a cloud zone 401-402 mayinclude one or more computer servers 403, such as the virtualizationservers 301 described above, which may be configured to create and hostvirtual machine instances. The physical network resources in a cloudzone 401 or 402 may include one or more network elements 405 (e.g.,network service providers) comprising hardware and/or softwareconfigured to provide a network service to cloud customers, such asfirewalls, network address translators, load balancers, virtual privatenetwork (VPN) gateways, Dynamic Host Configuration Protocol (DHCP)routers, and the like. The storage resources in the cloud zone 401-402may include storage disks (e.g., solid state drives (SSDs), magnetichard disks, etc.) and other storage devices.

The example cloud computing environment shown in FIG. 4 also may includea virtualization layer (e.g., as shown in FIGS. 1-3) with additionalhardware and/or software resources configured to create and managevirtual machines and provide other services to customers using thephysical resources in the cloud. The virtualization layer may includehypervisors, as described above in FIG. 3, along with other componentsto provide network virtualizations, storage virtualizations, etc. Thevirtualization layer may be as a separate layer from the physicalresource layer, or may share some or all of the same hardware and/orsoftware resources with the physical resource layer. For example, thevirtualization layer may include a hypervisor installed in each of thevirtualization servers 403 with the physical computing resources. Knowncloud systems may alternatively be used, e.g., WINDOWS AZURE (MicrosoftCorporation of Redmond Wash.), AMAZON EC2 (Amazon.com Inc. of Seattle,Wash.), IBM BLUE CLOUD (IBM Corporation of Armonk, N.Y.), or others.

FIG. 5 is a block diagram of example system 500 in which one or moreresource management services 502 may manage and streamline access by oneor more clients 504 to one or more resource feeds 506 (via one or moregateway services 508) and/or one or more software-as-a-service (SaaS)applications 510. In particular, resource management service(s) 502 mayemploy identity provider 512 to authenticate the identity of a user ofclient 504 and, following authentication, identify one of more resourcesthe user is authorized to access. In response to the user selecting oneof the identified resources, resource management service(s) 502 may sendappropriate access credentials to requesting client 504, and client 504may then use those credentials to access the selected resource. Forresource feed(s) 506, client 504 may use the supplied credentials toaccess the selected resource via gateway service 508. For SaaSapplication(s) 510, client 504 may use the credentials to access theselected application directly.

Client(s) 504 may be any type of computing devices capable of accessingresource feed(s) 506 and/or the SaaS application(s) 510, and may, forexample, include a variety of desktop or laptop computers, smartphones,tablets, etc., including the various devices, terminals, and clientsthat have been discussed above. Resource feed(s) 506 may include any ofnumerous resource types and may be provided from any of numerouslocations. In some embodiments, for example, resource feed(s) 506 mayinclude one or more systems or services for providing virtualapplications and/or desktops to client(s) 504, one or more filerepositories and/or file sharing systems, one or more secure browserservices, one or more access control services for SaaS applications 510,one or more management services for local applications on client(s) 504,one or more internet enabled devices or sensors, etc. Each of resourcemanagement service(s) 502, the resource feed(s) 506, gateway service(s)508, the SaaS application(s) 510, and identity provider 512 may belocated within an on-premises data center of an organization for whichsystem 500 is deployed, within one or more cloud computing environments,or elsewhere.

FIG. 6A is a block diagram showing an example implementation of system500 shown in FIG. 5, in which various resource management services 502as well as a gateway service 508 are located within cloud computingenvironment 602. Cloud computing environment 602 may, for example,include Microsoft Azure Cloud®, Amazon Web Services®, Google Cloud®, orIBM Cloud®.

For any of illustrated components that are not based within the cloudcomputing environment 602, cloud connectors (not shown) may be used tointerface those components with cloud computing environment 602. Suchcloud connectors may, for example, run on Windows Server® instanceshosted in resource locations and may create a reverse proxy to routetraffic between the site(s) and cloud computing environment 602. In theillustrated example, cloud-based resource management services 502 mayinclude client interface service 604, identity service 606, resourcefeed service 614, and single sign-on (SSO) service 608. As shown, insome embodiments, client 504 may use resource access application 610 tocommunicate with client interface service 604 as well as to present auser interface on client 504 that user 612 can operate to accessresource feed(s) 506 and/or SaaS application(s) 510. Resource accessapplication 610 may either be installed on client 504, or may beexecuted by client interface service 604 (or elsewhere in system 600A)and accessed using a web browser (not shown in FIG. 6A) on client 504.

As explained in more detail below, in some embodiments, resource accessapplication 610 and associated components may provide user 612 with apersonalized, all-in-one interface enabling instant and seamless accessto all the user's SaaS and web applications, files, virtual Windowsapplications, virtual Linux applications, desktops, mobile applications,Citrix Virtual Apps and Desktops®, local applications, and other data.

When resource access application 610 is launched or otherwise accessedby user 612, client interface service 604 may send a sign-on request toidentity service 606. In some embodiments, identity provider 512 may belocated on the premises of the organization for which system 600A isdeployed. Identity provider 512 may, for example, correspond to anon-premises Windows Active Directory®. In such embodiments, identityprovider 512 may be connected to cloud-based identity service 606 usinga cloud connector (not shown in FIG. 6A), as described above. Uponreceiving a sign-on request, identity service 606 may cause resourceaccess application 610 (via client interface service 604) to prompt user612 for the user's authentication credentials (e.g., user-name andpassword). Upon receiving the user's authentication credentials, clientinterface service 604 may pass the credentials along to identity service606, and identity service 606 may, in turn, forward them to identityprovider 512 for authentication, for example, by comparing them againstan Active Directory domain. Once identity service 606 receivesconfirmation from identity provider 512 that the user's identity hasbeen properly authenticated, client interface service 604 may send arequest to resource feed service 614 for a list of subscribed resourcesfor user 612.

In other embodiments (not illustrated in FIG. 6A), identity provider 512may be a cloud-based identity service, such as a Microsoft Azure ActiveDirectory®. In such embodiments, upon receiving a sign-on request fromclient interface service 604, identity service 606 may, via clientinterface service 604, cause client 504 to be redirected to thecloud-based identity service to complete an authentication process. Thecloud-based identity service may then cause client 504 to prompt user612 to enter the user's authentication credentials. Upon determining theuser's identity has been properly authenticated, the cloud-basedidentity service may send a message to resource access application 610indicating the authentication attempt was successful, and resourceaccess application 610 may then inform client interface service 604 ofthe successfully authentication. Once identity service 606 receivesconfirmation from client interface service 604 that the user's identityhas been properly authenticated, client interface service 604 may send arequest to resource feed service 614 for a list of subscribed resourcesfor user 612.

For each configured resource feed, resource feed service 614 may requestan identity token from single sign-on service 608. Resource feed service614 may then pass the feed-specific identity tokens it receives to thepoints of authentication for respective resource feeds 506. Eachresource feed 506 may then respond with a list of resources configuredfor the respective identity. Resource feed service 614 may thenaggregate all items from the different feeds and forward them to clientinterface service 604, which may cause the resource access application610 to present a list of available resources on a user interface ofclient 504. The list of available resources may, for example, bepresented on the user interface of client 504 as a set of selectableicons or other elements corresponding to accessible resources. Theresources so identified may, for example, include one or more virtualapplications and/or desktops (e.g., Citrix Virtual Apps and Desktops®,VMware Horizon®, Microsoft RDS®, etc.), one or more file repositoriesand/or file sharing systems (e.g., Sharefile®), one or more securebrowsers, one or more internet enabled devices or sensors, one or morelocal applications installed on client 504, and/or one or more SaaSapplications 510 to which user 612 has subscribed. The lists of localapplications and SaaS applications 510 may, for example, be supplied byresource feeds 506 for respective services that manage which suchapplications are to be made available to user 612 via resource accessapplication 610. Examples of SaaS applications 510 that may be managedand accessed as described herein include Microsoft Office 365®applications, SAP® SaaS applications, Workday® applications, etc.

For resources other than local applications and SaaS application(s) 510,upon user 612 selecting one of the listed available resources, resourceaccess application 610 may cause client interface service 604 to forwarda request for the specified resource to resource feed service 614. Inresponse to receiving such a request, resource feed service 614 mayrequest an identity token for the corresponding feed from single sign-onservice 608. Resource feed service 614 may then pass the identity tokenreceived from single sign-on service 608 to client interface service 604where a launch ticket for the resource may be generated and sent toresource access application 610. Upon receiving the launch ticket,resource access application 610 may initiate a secure session to gatewayservice 508 and present the launch ticket. When gateway service 508 ispresented with the launch ticket, it may initiate a secure session tothe appropriate resource feed 506 and present the identity token to thatfeed to seamlessly authenticate user 612. Once the session initializes,client 504 may proceed to access the selected resource.

When user 612 selects a local application, resource access application610 may cause the selected local application to launch on client 504.When user 612 selects Saas application 510, resource access application610 may cause client interface service 604 request a one-time uniformresource locator (URL) from gateway service 508 as well as a preferredbrowser for use in accessing SaaS application 510. After gateway service508 returns the one-time URL and identifies the preferred browser,client interface service 604 may pass that information along to resourceaccess application 610. Client 504 may then launch the identifiedbrowser and initiate a connection to gateway service 508. Gatewayservice 508 may then request an assertion from single sign-on service608. Upon receiving the assertion, gateway service 508 may cause theidentified browser on client 504 to be redirected to the logon page foridentified SaaS application 510 and present the assertion. SaaSapplication 510 may then contact gateway service 508 to validate theassertion and authenticate user 612. Once user 612 has beenauthenticated, communication may occur directly between the identifiedbrowser and selected SaaS application 510, thus allowing user 612 to useclient 504 to access selected SaaS application 510.

In some embodiments, the preferred browser identified by gateway service508 may be a specialized browser embedded in resource access application610 (e.g., when resource application is installed on the client 504) orprovided by one of resource feeds 506 (e.g., when resource application610 is located remotely), e.g., via a secure browser service. In suchembodiments, SaaS applications 510 may incorporate enhanced securitypolicies to enforce one or more restrictions on the embedded browser.Examples of such policies may include (1) requiring use of thespecialized browser and disabling use of other local browsers, (2)restricting clipboard access, e.g., by disabling cut/copy/pasteoperations between the application and the clipboard, (3) restrictingprinting (e.g., by disabling the ability to print from within thebrowser), (4) restricting navigation (e.g., by disabling the next and/orback browser buttons), (5) restricting downloads (e.g., by disabling theability to download from within SaaS application 510), and (6)displaying watermarks (e.g., by overlaying a screen-based watermarkshowing the username and IP address associated with client 504 such thatthe watermark will appear as displayed on the screen if the user triesto print or take a screenshot). Further, in some embodiments, when auser selects a hyperlink within SaaS application 510, the specializedbrowser may send the URL for the link to an access control service(e.g., implemented as one of resource feed(s) 506) for assessment of itssecurity risk by a web filtering service. For approved URLs, thespecialized browser may be permitted to access the link. For suspiciouslinks, however, the web filtering service may have client interfaceservice 604 send the link to a secure browser service, which may start anew virtual browser session with client 504, and thus allow the user toaccess the potentially harmful linked content in a safe environment.

In some embodiments, in addition to or in lieu of providing user 612with a list of resources that are available to be accessed individually,as described above, user 612 may instead be permitted to choose toaccess a streamlined feed of event notifications and/or availableactions that may be taken with respect to events that are automaticallydetected with respect to one or more of the resources. This streamlinedresource activity feed, which may be customized for each user 612, mayallow users to monitor important activity involving all of theirresources-Saas applications, web applications, Windows applications,Linux applications, desktops, file repositories and/or file sharingsystems, and other data through a single interface, without needing toswitch context from one resource to another. Further, eventnotifications in a resource activity feed may be accompanied by adiscrete set of user-interface elements, e.g., “approve,” “deny,” and“see more detail” buttons, allowing a user to take one or more simpleactions with respect to each event right within the user's feed. In someembodiments, such a streamlined, intelligent resource activity feed maybe enabled by one or more micro-applications, or “microapps,” that caninterface with underlying associated resources using APIs or the like.The responsive actions may be user-initiated activities that are takenwithin the microapps and that provide inputs to the underlyingapplications through the API or other interface. The actions a userperforms within the microapp may, for example, be designed to addressspecific common problems and use cases quickly and easily, adding toincreased user productivity (e.g., request personal time off, submit ahelp desk ticket, etc.). In some embodiments, notifications from suchevent-driven microapps may additionally or alternatively be pushed toclients 504 to notify user 612 of something that requires the user'sattention (e.g., approval of an expense report, new course available forregistration, etc.).

FIG. 6B is a block diagram similar to that shown in FIG. 6A but in whichthe available resources (e.g., SaaS applications, web applications,Windows applications, Linux applications, desktops, file repositoriesand/or file sharing systems, and other data) are represented by a singlebox 616 labeled “systems of record,” and further in which severaldifferent services are included within resource management services 502.As explained below, the services shown in FIG. 6B may enable theprovision of a streamlined resource activity feed and/or notificationprocess for client 504. In the example shown, in addition to clientinterface service 604 discussed above, the illustrated services mayinclude microapp service 618, data integration provider service 620, acredential wallet service 622, active data cache service 624, analyticsservice 626, and notification service 628. In various embodiments, theservices shown in system 600B of FIG. 6B may be employed either inaddition to or instead of the various services shown in FIG. 6A.

In some embodiments, a microapp may be a single use case app madeavailable to users to streamline functionality from complex enterpriseapplications. Microapps may, for example, utilize APIs available withinSaaS, web, or home-grown applications allowing users to see contentwithout needing a full launch of the application or the need to switchcontext. Absent such microapps, users would need to launch anapplication, navigate to the action they need to perform, and thenperform the action. Microapps may streamline routine tasks forfrequently performed actions and provide users the ability to performactions within resource access application 610 without having to launchthe native application. The system shown in FIG. 6B may, for example,aggregate relevant notifications, tasks, and insights, and thereby giveuser 612 a dynamic productivity tool. In some embodiments, the resourceactivity feed may be intelligently populated by utilizing machinelearning and artificial intelligence (AI) algorithms. Further, in someimplementations, microapps may be configured within cloud computingenvironment 602, thus giving administrators a powerful tool to createmore productive workflows, without the need for additionalinfrastructure. Whether pushed to a user or initiated by a user,microapps may provide short cuts that simplify and streamline key tasksthat would otherwise require opening full enterprise applications. Insome embodiments, out-of-the-box templates may allow administrators withAPI account permissions to build microapp solutions targeted for theirneeds. Administrators may also, in some embodiments, be provided withthe tools they need to build custom microapps.

Referring to FIG. 6B, systems of record 616 may represent theapplications and/or other resources that resource management services502 may interact with to create microapps. These resources may be SaaSapplications, legacy applications, and/or homegrown applications, andcan be hosted on-premises or within a cloud computing environment.Connectors with out-of-the-box templates for several applications may beprovided and integration with other applications may additionally oralternatively be configured through a microapp page builder. Such amicroapp page builder may, for example, connect to legacy, on-premises,and SaaS systems by creating streamlined user workflows via microappactions. Resource management services 502, and in particular dataintegration provider service 620, may, for example, support REST API,JSON, OData-JSON, and 6ML. As explained in more detail below, dataintegration provider service 620 may also write back to the systems ofrecord, for example, using OAuth2 or a service account.

In some embodiments, microapp service 618 may be a single-tenant serviceresponsible for creating the microapps. Microapp service 618 may sendraw events, pulled from systems of record 616, to analytics service 626for processing. Microapp service 618 may, for example, periodically pullactive data from systems of record 616.

In some embodiments, active data cache service 624 may be single-tenantand may store all configuration information and microapp data. It may,for example, utilize a pertinent database encryption key and per-tenantdatabase credentials. In some embodiments, credential wallet service 622may store encrypted service credentials for systems of record 616 anduser OAuth2 tokens.

In some embodiments, data integration provider service 620 may interactwith systems of record 616 to decrypt end-user credentials and writeback actions to systems of record 616 under the identity of theend-user. The write-back actions may, for example, utilize a user'sactual account to ensure all actions performed are compliant with datapolicies of the application or other resource being interacted with.

In some embodiments, analytics service 626 may process the raw eventsreceived from microapps service 618 to create targeted scorednotifications and send such notifications to notification service 628.

Finally, in some embodiments, notification service 628 may process anynotifications it receives from analytics service 626. In someimplementations, notification service 628 may store the notifications ina database to be later served in a notification feed. In otherembodiments, notification service 628 may additionally or alternativelysend the notifications out immediately to client 504 as a pushnotification to user 612.

In some embodiments, a process for synchronizing with systems of record616 and generating notifications may operate as follows. Microappservice 618 may retrieve encrypted service account credentials forsystems of record 616 from credential wallet service 622 and request async with data integration provider service 620. Data integrationprovider service 620 may then decrypt the service account credentialsand use those credentials to retrieve data from systems of record 616.Data integration provider service 620 may then stream the retrieved datato microapp service 618. Microapp service 618 may store the receivedsystems of record data in active data cache service 624 and also sendraw events to analytics service 626. Analytics service 626 may createtargeted scored notifications and send such notifications tonotification service 628. Notification service 628 may store thenotifications in a database to be later served in a notification feedand/or may send the notifications out immediately to client 504 as apush notification to user 612.

In some embodiments, a process for processing a user-initiated actionvia a microapp may operate as follows. Client 504 may receive data frommicroapp service 618 (via client interface service 604) to renderinformation corresponding to the microapp. Microapp service 618 mayreceive data from active data cache service 624 to support thatrendering. User 612 may invoke an action from the microapp, causingresource access application 610 to send that action to microapp service618 (via client interface service 604). Microapp service 618 may thenretrieve from credential wallet service 622 an encrypted Oauth2 tokenfor the system of record for which the action is to be invoked, and maysend the action to data integration provider service 620 together withthe encrypted Oath2 token. Data integration provider service 620 maythen decrypt the Oath2 token and write the action to the appropriatesystem of record 616 under the identity of user 612. Data integrationprovider service 620 may then read back changed data from the written-tosystem of record and send that changed data to microapp service 618.Microapp service 618 may then update active data cache service 624 withthe updated data and cause a message to be sent to resource accessapplication 610 (via client interface service 604) notifying user 612that the action was successfully completed.

In some embodiments, in addition to or in lieu of the functionalitydescribed above, resource management services 502 may provide users theability to search for relevant information across all files andapplications. A simple keyword search may, for example, be used to findapplication resources, SaaS applications, desktops, files, etc. Thisfunctionality may enhance user productivity and efficiency asapplication and data sprawl is prevalent across all organizations. Inother embodiments, in addition to or in lieu of the functionalitydescribed above, resource management services 502 may enable virtualassistance functionality that allows users to remain productive and takequick actions. Users may, for example, interact with the “VirtualAssistant” and ask questions such as “What is Bob Smith's phone number?”or “What absences are pending my approval?” Resource management services502 may, for example, parse these requests and respond because they areintegrated with multiple systems on the back-end. In some embodiments,users may be able to interact with the virtual assistance through eitherthe resource access application 610 or directly from another resource,such as Microsoft Teams®. This feature may allow employees to workefficiently, stay organized, and deliver only the specific informationthey're looking for.

Web Client with Response Latency Awareness

FIG. 7 depicts a block diagram illustrating an example system for makingand responding to web requests. According to example system 700, clientdevice 701 may interact with server device 702 (optionally via network703). Client device 701 may be, for example, any one of the variousclient devices as described above, such as client devices 105, 107, 109;terminals 240; client computers 411, 412, 413, 414; and/or client 504.Server device 702 may be, for example, any one of the various servicerdevices as described above, such as data server 103, web server 105,computing device 201, servers 206, virtualization server 301, cloudmanagement server 410, host servers 403, storage resources 404, networkelements 405, resource management service 502, resource feed 506,gateway service 508, identity provider 512, and/or cloud computingenvironment 602. Although client device 701 and server device 702 aredepicted as separate devices in FIG. 7, in some embodiments, client 701and server 702 may reside within one physical device or within closeproximity from each other. Client device 701 and/or server device 702may be implemented in a virtual machine.

Network 703 may be any type of wired or wireless communicationinfrastructure that allows client device 701 and server device 702 toexchange control signals and/or data. For example, network 703 may be alocal area network (LAN), a virtual local area network (VLAN), a widearea network (WAN), the Internet, etc. Network 703 may support webcommunications using Hypertext Transfer Protocol (HTTP).

Client device 701 may include web client 704 and message handler 705.One or more components of client device 701 may be implemented withhardware, software, or a combination of both. Web client 704 may be anyinstance of application that is capable of making web requests. Webclient 704 may be an HTTP client. For example, web client 704 may be aweb browser, an email client, a calendar application, a social mediaapplication, a digital map application, a productivity application, amessaging application, a communications application, a databaseapplication, an information retrieval application, a microapp, etc. Webclient 704 may be a desktop application or a mobile application. Messagehandler 705 may be a software and/or hardware module that handlesmessaging between web client 704 and web service 706 of server device702. Message handler 705 may be, for example, an HTTP message handler(e.g., of HttpMessageHandler class) on the NET Framework developed byMICROSOFT CORPORATION of Redmond, Wash. Message handler 705 may becapable of performing the exponential moving average (EMA) function aswell as storing and recalling EMA values. Web client 704 may use messagehandler 705 to invoke the make request (e.g., make HTTP request)function to send out a web request to web service 706. In response,message handler may use the EMA function to determine whether or not tothrottle the web request. After message handler 705 sends out the webrequest (e.g., an HTTP request) to web service 706, message handler 705may receive a web response (e.g., an HTTP response) from web service706. Based on a timer that was initiated when the web request was sentout, message handler 705 may determine a response time for the webresponse. The response time may be recorded and an updated EMA value maybe determined based on the response time. Message handler 705 mayforward an external service response code (e.g., 200 OK, 400 BadRequest, 404 Not Found, etc.) to web client 704. If no response isreceived by message handler 705 before the timer expires, messagehandler 705 may return an error code (e.g., 408 Request Timeout) to webclient 704.

Server device 702 may include web service 706. Web service 706 may beimplemented with hardware, software, or a combination of both. Forexample, web service 706 may be a web server, an application server, astorage resource, etc. Web service 706 may be an external HTTP servicethat receives HTTP requests and sends out appropriate HTTP responses.

FIG. 8 depicts a block diagram illustrating an example flow of managingweb requests with respect to an example system. In example system 800,message handler 801 may interact with web client 802 and web service 803to manage web requests and web request responses. Message handler 801,web client 802, and web service 803 may respectfully correspond tomessage handler 705, web client 704, and web service 706 as describedwith reference to FIG. 7. Message handler 801 may further include EMAfunction 804. EMA function 804 may be implemented with software,hardware, or a combination of both to calculate exponential movingaverage values of recent web request response times. Although EMA isused as an example of a function for determining an average valuethroughout this disclosure, other functions may also be used, such as asimple moving average, a cumulative moving average, a weighted movingaverage, etc. EMA function 804 may be capable of storing a history ofresponse times and/or EMA values. Storage of such values may be donewithin or outside of EMA function 804, such as in message handler 801,in client device 701, or outside client device 701 (e.g., cloudstorage). Although many of the steps shown in FIG. 8 are described asbeing performed by message handler 801 throughout the presentdisclosure, other components of a client device (e.g., client device701) or another device may perform one or more of these steps. Forexample, all or part of the functionalities of message handler 801 maybe integrated into web client 802.

Steps 805 through 808 may represent the outbound flow algorithm of theclient. At step 805, web client 802 may send out a web request. Forexample, message handler 801 may invoke message handler 801 to invoke amake request command. In some embodiments, web client 802 may make a webrequest via an API call and message handler 801 may receive and/orintercept the call to process it. The web request may be an HTTPrequest. The web request may include, for example, a Uniform ResourceIdentifier (URI) or Uniform Resource Locator (URL), an HTTP verb (e.g.,GET, HEAD, POST, PUT, DELETE, CONNECT, OPTIONS, TRACE, etc.), an HTTPheader having one or more header fields, etc. The web request may alsoinclude a parameter specifying how the request is to be categorized.This parameter may be a data reference that allows EMA function 804 tocategorize web requests.

At step 806, EMA function 804 may determine whether to throttle the webrequest. EMA function 804 may access the current EMA of the previousrequest response times and determine whether or not the web request isto be throttled. For example, determination of whether to throttle theweb request may be based on a formula, A_(C)+(A_(C)×C)>T, where A_(C) isthe current EMA of past response times, C is a smoothing constant, and Tis a timer value. If this formula is satisfied, the web request may bethrottled (806—YES). On the other hand, if the formula is not satisfied,the web request may be sent out without being throttled (806—NO). Thecurrent EMA may be the latest or updated EMA value that is calculatedbased on past web request response times. The smoothing constant be aconstant value between 0 and 1 that determines how much weight is to beassigned to more recent response time values. Thus, the higher thesmoothing constant is (i.e., closer to 1) the greater weight is given tothe most recently measured response time value. The smoothing constantvalue may, for example, be determined by a formula, C=2+(N+1), where Nrepresents a weight value. The higher the value of N is, the greaterweight will be assigned to older response time values. For example, Nmay be 7 and C may be 0.25. In another example, N may be 3 and C may be0.5. The smoothing constant may be determined other formulas. The timervalue (also referred to as a timeout value) may be the time thresholdwithin which a response to the web request is expected to arrive. Forexample, the timer value may be 1,000 milliseconds.

EMA function 804 may keep track of multiple EMA values for differentcategories of web requests to allow selective web request throttling.For example, it may be possible for message handler 801 tosimultaneously allow a first category of web requests (e.g., based onthe EMA for the first category) while disallowing (e.g., throttling) asecond category of web requests (e.g., based on the EMA for the secondcategory). The categories may be determined based on a full URL, a URLpath, a query string, a header, and/or a verb associated with webrequests. The categories can be but may not necessarily be mutuallyexclusive, and a given web request may belong to one or more categories.Message handler 801 may automatically generate new categories based onnew web requests being received.

If it is determined that the web request is to be throttled (806—YES),then at step 807, message handler 801 may respond to web client 802 withan error code. The error code may be an HTTP response status code suchas HTTP 429 Too Many Requests. Thus, by using EMA function 804, thenumber of web requests being sent to web service 803 may be scaled backif the current EMA value gets too high. Alternatively, when EMA function804 determines to throttle web requests, a small percentage of webrequests may still be sent out to web service 803 instead of disallowing100% of all web requests being received from web client 802. Forexample, depending on the throttling ratio setting (e.g., 5%, 15%, 30%,50%, 75%, 100%, etc.), message handler 801 may still send out a certainportion of the received web requests to web service 803 instead ofresponding to web client 802 with an error code every time. As anexample, if message handler 801 is set up to reject 80% of web requestswhen being throttled, one out of every five web requests may be sent toweb service 803 even when EMA function 804 determines that web requestsare to be throttled.

If it is determined that the web request is not to be throttled(806—NO), message handler 801 may start a timer at step 808 and send theweb request to web service 803. The start time of the timer may bestored for later use when a response time is calculated. The timer maybe uniquely associated with the web request and/or its associatedcategory. Thus, if multiple web requests are made, multiple independenttimers may be initiated to keep track of the multiple requestssimultaneously. The web request may be sent to web service 803 via anetwork, such as network 703 shown in FIG. 7. However, message handler801 and web service 803 may be located in the same physical or virtualdevice.

Steps 809 through 817 may represent the inbound flow algorithm of theclient. At step 809, message handler 801 may determine whether a webresponse corresponding to the web request has been received from webservice 803 (e.g., from the target URL or URI). The web response may bean HTTP response status code (e.g., 100 Continue, 200 OK, 300 MultipleChoice, 400 Bad Request, 403 Forbidden, 404 Not Found, etc.). If webservice 803 has indeed sent a web response in response to the previousweb request (809—YES), message handler 801 may record the response timeof the web response at step 811. The response time may be determined bysubtracting the previously recorded start time of the timer from thecurrent time. In some embodiments, an indication of the category may berecorded together with the response time so that appropriate EMAvalue(s) corresponding to the category (and only those EMA values) maybe updated later. At step 812, the newly recorded response time (e.g.,current time−timer start time) may be used to update the EMA value.Thus, the newly updated EMA value may become the new “current” EMA valuefor the purpose of determining whether to throttle the next web requestat step 806. Updating of an EMA value may be performed based on aformula, A_(U)=(R−A_(C))×C+A_(C), where A_(U) is the updated (i.e., newor next) exponential moving average, R is the new response time, A_(C)is the current (i.e., old or previous) exponential moving average, and Cis the smoothing constant as discussed above. In this way, every time anew response time is recorded, a newly updated EMA value may becalculated, and the smoothing constant may determine how far back intime EMA function 804 should take into account when using past responsetime values. Finally at step 813, message handler 801 may forward theweb response received from web service 803 to web client 802.

If a web response is not received at step 809 (809—NO), however, messagehandler 801 may further determine at step 814 whether the timer hasexpired. Message handler 801 may calculated the elapsed time since thetimer started (e.g., current time−timer start time), and compare theelapsed time against the timer timeout value (e.g., 1,000 milliseconds).If the timer has not expired (e.g., elapsed time<timeout value)(814—NO), then the process may return to step 809 to continue to monitorincoming data traffic from web service 803. If the timer has expired(e.g., elapsed time≥timeout value) (814—YES), then at step 815, messagehandler 801 may record the timer value (e.g., the timeout value) as theresponse time associated with the corresponding web request that wassent out to web service 803. In some embodiments, an indication of thecategory may be recorded together with the response time so thatappropriate EMA value(s) corresponding to the category (and only thoseEMA values) may be updated later. At step 816, the newly recordedresponse time may be used by EMA function 804 to update its EMA value.Thus, the newly updated EMA value may become the new “current” EMA valuefor the purpose of determining whether to throttle the next web requestat step 806. Similar to step 812, updating of an EMA value may beperformed based on the formula, A_(U)=(R−A_(C))×C+A_(C), where A_(U) isthe updated (i.e., new or next) exponential moving average, R is the newresponse time, A_(C) is the current (i.e., old or previous) exponentialmoving average, and C is the smoothing constant. At step 817, messagehandler 801 may reply to web client 802 with an error code. The errorcode may be an HTTP response status code such as HTTP 408 RequestTimeout. Thus, web client 802 may receive an error response (e.g., 408Request Timeout) more quickly (e.g., when the timer expires) rather thanhaving to wait for a longer time for web service 803 to issue an errorresponse, thereby reducing latency and also reducing the amount oftraffic being exchanged between the client and the server.

The various steps shown in FIG. 8 and further described above may beperformed in any order, including an order in which one or more stepsare modified, omitted or added. For example, the determination of step814 may be performed prior to or concurrently with the determination ofstep 809. As another example, the EMA updating steps of 812 and 816 maybe performed after steps 813 and 817, respectively, or even after thenext web request is received at step 805.

FIG. 9 depicts a table with illustrative web request response times andother related data. Shown in example table 900 are response time 901,previous EMA 902, current EMA 903, adjusted EMA, and throttle status905. In this particular example, the smoothing constant is set at 0.25,and the timeout value is set at 1,000 milliseconds, but other values maybe used. Column 901 of table 900 shows response time values as measuredby the client device (e.g., client device 701, message handler 705,message handler 801). Response time 901 represents the amount of timebetween the transmission of a web request and the receipt of thecorresponding web response. Previous EMA 902 represents the exponentialmoving average that was previously calculated before the correspondingresponse time 901 was recorded. In other words, a previous EMA 902 valuein any given row may be equal to the previous row's current EMA 903value. Current EMA 903 represents the newly updated EMA value based onthe latest response time 901. For example, current EMA 903 may bedetermined by the formula, A_(C)=(R−A_(P))×C+A_(P), where A_(C) iscurrent (i.e., updated, new, or next) EMA 903, R is response time 901,A_(P) is previous (i.e., old or previously “current”) EMA 902, and C isthe smoothing constant (e.g., 0.25).

Adjusted EMA 904 represents the value that is to be compared against thetimeout value (e.g., 1,000 msec) for the purpose of determining whetherto throttle the next web request. For example, adjusted EMA 904 may bedetermined by the formula, A_(C)+(A_(C)×C), where A_(C) is current EMA903, C is the smoothing constant. By adjusting current EMA 903 based onthe smoothing constant, a buffer zone may be created such that thethrottle may be preemptively engaged slightly before current EMA 903actually exceeds the timeout value. Throttle status 905 may representthe result of a determination of whether to throttle the next webrequest (i.e., “ON”) or not throttle the next request (i.e., “OFF”).When the web request is throttled, all or part of future web requestsmay be disallowed depending on the throttling ratio setting (e.g., 5%,15%, 30%, 50%, etc.). Throttling of web requests may be determined basedon the comparison of adjusted EMA 904 against the timeout value. Forexample, if EMA 904 is greater than and/or equal to the timeout value,throttle status 905 may be set to “ON.” Conversely, if EMA 904 is lessthan and/or equal to the timeout value, throttle status 905 may be setto “OFF.” Alternatively, current EMA 903, instead of adjusted EMA 904,may be compared against the timeout value to determine throttle status905.

Data such as table 900 may be stored in the client device or in storageoutside of the client device. Multiple sets of data may be store on theper-category basis. For example, table 900 may represent response timevalues (and their associated data) pertaining to one category of webrequests may be stored, and a separate set of response time values (andtheir associated data) pertaining to another category may be alsostored.

FIG. 10 depicts a graph with illustrative web request response times andother related data. In particular example graph 1000 corresponds to datashown in table 900 of FIG. 9. In this example, the vertical axis ofgraph 1000 represents time in milliseconds, and the horizontal axisrepresents the sequence in which web response times are recorded. Whilethe curved line representing the adjusted EMA is above the horizontalline representing the timeout value, the web requests may be throttled.It may be observed from graph 1000 that the vertical movements of thecurrent EMA values and the adjusted EMA values are more gradual than therise and fall of raw response time values, and thus the sudden spikesand dips are more smoothed out. Consequently, even when the responsetime dips below the timeout value of 1,000 milliseconds at sequencenumber 23 and onward in this example, the throttle may stay on for farlonger until sequence number 29.

FIG. 11 depicts example category types for managing web requests. Asdiscussed above, a client device (e.g., a message handler of the clientdevice) may receive, from a web client, a web request and an indicationof a category. The EMA function of the message handler may maintainseparate sets of response times according to different categories. TheEMA function may also maintain separate EMA values according todifferent categories. Each category may be represented by the uniquetuple {CATEGORY, Category Reference}, where CATEGORY is a keyword thatindicates a category type, and Category Reference is a parameter thatfurther defines the category. The Category Reference may include aregular expression. The client device may have a database that maps thekey {CATEGORY, Category Reference} to the value {current EMA, throttlestatus}. The category types may be, for example, FULL_URL, URL_PATH,QUERY_STRING, HEADER, VERB, etc. FULL_URL category type 1101 may be adefault category type if no category indication is provided with a webrequest. FULL_URL category type 1101 may be defined by itsparameter<request URL>, which is a full URL included in the web request.Some examples of this category type may include {FULL_URL,www.test.com/examplepath/en/home.html?key=1029}, {FULL_URL,http://web.example.com/foo/bar.aspx?search=keyword&index=1114},{FULL_URL, simpleaddress.net}, etc. URL_PATH category type 1102 may bedefined by a partial URL such as a URL path. The parameter may berepresented by a regular expression and any URL that matches the regularexpression may belong in the corresponding category. Some examples ofthis category type may include {URL_PATH, (/?[a-z0-9\-._˜%!$&′()*+,;=@]+(/[a-z0-9\-._˜%!$&′( )*+,;=:@]+)*/?|/)}, {URL_PATH,/path/home.html}, {URL_PATH,(/(path1|path2|path3))+/target(.html?|.php|.aspx)?}, etc.

QUERY_STRING category type 1103 may be defined by its parameter <querystring key>, which may assign values to specified parameters in a URL.Some examples of this category type may include {QUERY_STRING, search=},{QUERY_STRING, q=04160826},{QUERY_STRING, code=04210908?expired=yes},etc. HEADER category type 1104 may be defined by its parameter <headerkey>, which is a component of the header section of the web requestmessage. The header key may also be referred to as a header field. Someexamples of this category type may include {HEADER, Host}, {HEADER,Accept-Language:(en|sp|fr|kr)},{HEADER, Cookie}, etc. VERB category type1105 may be defined by its parameter <verb value>, which indicates adesired action to be performed. The verb is also referred to as amethod. Some examples of this category type may include {VERB, GET},{VERB, PUT}, {VERB, CONNECT}, etc.

Having disclosed some basic system components and concepts, FIGS. 12-13illustrate methods or algorithms that may be performed to implementvarious features described herein. For the sake of clarity, the methodis described in terms of example system 700 as shown in FIG. 7configured to practice the method or algorithm. For example, clientdevice 701 and/or message handler 705 may perform the steps disclosedherein. Other devices, including message handler 801 of FIG. 8, may alsoperform these steps. The steps outlined herein are exemplary and can beimplemented in any combination thereof, including combinations thatexclude, add, or modify certain steps. The steps can be performed in anyorder.

FIG. 12 depicts an outbound flow algorithm of an illustrative method forhandling web requests. At step, 1201, the system may receive a webrequest. The web request may be received from a web client. The webrequest may be an HTTP request. The web request may include anindication of a category associated with the web request. At step 1202,the system may determine an EMA. The determination of the EMA may bebased on one or more past web response times. The EMA and the past webresponse times being referenced may be specific to the category to whichthe web request belongs. The EMA may be an updated EMA that wascalculated based on the most recent response time.

At step 1203, the system may determine whether or not to allow the webrequest to be sent to the server. The determination may be based on theEMA and a timer timeout value. For example, the throttling determiningmay be based on the formula, A_(C)+(A_(C)×C)>T, where A_(C) is the EMAof the past response times, C is a smoothing constant, and T is atimeout value. The smoothing constant may be determined based on theformula, C=2÷(N+1), where Nis a weight value. 10. The system maydetermine an EMA associated with a category to which the requestbelongs, among multiple EMA values associated with respectivecategories. If there is not current EMA, then the client device may setthe current EMA to 0, create a new key/value entry in the database, andallow the web request by default.

When the throttling formula is satisfied (e.g., A_(C)+(A_(C)×C)>T),throttling may be engaged and all or a portion (e.g., according to athrottling ratio) of web requests may be rejected or disallowed fromreaching the server (1203—NO), and the system may send an error responseto the web client at step 1205 and then wait for the next web request.The error response may be an HTTP response status code indicating toomany requests (e.g., HTTP 429 Too Many Requests). Optionally, even whenthe formula is satisfied and throttling is engaged, a certain percentage(e.g., according to the predetermined throttling ratio) of web requestsmay still be allowed to be sent (1204—YES). When the formula is notsatisfied (e.g., A_(C)+(A_(C)×C)≤T), throttling is disengaged and theweb request may be allowed to be sent (1203—YES). At step 1204, based onthe determination to allow the web request, the system may send the webrequest to the server. The server may be a web server. The web requestmay be sent to the server via a network such as the Internet. When theweb request is sent, a timer may be initiated. The start time of thetimer may be recorded such that it may be used later to calculate aresponse time.

FIG. 13 depicts an inbound flow algorithm of an illustrative method forhandling web responses. At step 1301, the system may determine whetheror not a response to the web request has been received. Specifically,the system may determine whether or not a response to the web requesthas been received from the server before the timer expired (e.g., timervalue>timeout value). The response may be a web response (e.g., an HTTPresponse) from the server. If the response is received before the timerexpires (1301—YES), then at step 1302, the system may determine aresponse time based on the received response. Specifically, the systemmay calculate the response time by subtracting the timer start timevalue from the time of the response's receipt. The system may store(e.g., record) the resulting value as the response time associated withthe response. If, on the other hand, the time expires before receiving aresponse from the server (1301—NO), then at step 1303, the system maydetermine the response time based on the timer. For example, the systemmay record the timeout value as the response time.

At step 1304, the system may update the EMA. Specifically, the systemmay determine the updated EMA based on the response time and the currentEMA of previous response times based on the formula,A_(U)=(R−A_(C))×C+A_(C), where A_(U) is the updated EMA, R is theresponse time, A_(C) is the current EMA, and C is the smoothingconstant. The updated EMA may be stored in the database with a matchingkey (e.g., {CATEGORY, Category Reference}). The smoothing constant maybe determined based on the formula, C=2÷(N+1), where N is a weightvalue. The response time R may be an actual response time based on thereceived response or the timeout value after the timer expires withoutreceiving a response. The updated EMA may be used to determine whetheror not to allow the next web request. If a matching key (e.g.,{CATEGORY, Category Reference}) does not exist in the database, thesystem may create a new key/value entry in the database, set theresponse time as the current EMA, then disengage throttling. At step1305, the system may send a response to the web client. The response maybe the same response (e.g., web response) received from the server, orit may be an error code (e.g., an HTTP response status code) indicatingrequest timeout (e.g., HTTP 408 Request Timeout) in case the responsewas never received before the timer expired.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are described asexample implementations of the following claims.

What is claimed is:
 1. A method comprising: receiving, from a webclient, a first web request; determining, based on an exponential movingaverage of a plurality of past response times, whether to allow thefirst web request; sending, based on the determination, the first webrequest to a server; receiving, from the server, a response to the firstweb request; determining a response time associated with the response;determining, based on the response time and the exponential movingaverage of the plurality of past response times, an updated exponentialmoving average; and sending the response to the web client.
 2. Themethod of claim 1, wherein the first web request comprises a hypertexttransfer protocol (HTTP) request.
 3. The method of claim 1, wherein thesending the first web request comprises initiating a timer, and whereinthe determining the response time comprises: calculating the responsetime based on the timer; and recording the response time.
 4. The methodof claim 1, wherein the determining the updated exponential movingaverage is based on a formula, A_(U)=(R−A_(C))×C+A_(C), and whereinA_(U) is the updated exponential moving average, R is the response time,A_(C) is the exponential moving average of the plurality of pastresponse times, and C is a smoothing constant.
 5. The method of claim 4,wherein the smoothing constant is based on a formula, C=2÷(N+1), andwherein N is a weight value.
 6. The method of claim 1, wherein the firstweb request comprises an indication of a category associated with thefirst web request, and wherein the plurality of past response times areassociated with the category.
 7. The method of claim 1, furthercomprising: receiving, from the web client and after receiving the firstweb request, a second web request; based on the updated exponentialmoving average, determining to disallow the second web request frombeing sent to the server; and sending an error response to the webclient.
 8. The method of claim 7, wherein the error response comprises ahypertext transfer protocol (HTTP) response status code indicating toomany requests.
 9. The method of claim 1, wherein the determining whetherto allow the first web request comprises at least one of: determining toallow the first web request based on a formula, A_(C)+(A_(C)×C)>T, beingsatisfied, wherein A_(C) is the exponential moving average of theplurality of past response times, C is a smoothing constant, and Tis atimeout value, or determining to disallow the first web request based onthe formula being not satisfied.
 10. The method of claim 1, wherein thedetermining whether to allow the first web request comprisesdetermining, among a plurality of exponential moving averages associatedwith respective categories, the exponential moving average associatedwith the category.
 11. An apparatus comprising: one or more processors;and memory storing instructions that, when executed by the one or moreprocessors, cause the apparatus to: receive, from a web client, a firstweb request; determine, based on an exponential moving average of aplurality of past response times, whether to allow the first webrequest; send, based on the determination, the first web request to aserver; receive, from the server, a response to the first web request;determine a response time associated with the response; determine, basedon the response time and the exponential moving average of the pluralityof past response times, an updated exponential moving average; and sendthe response to the web client.
 12. The apparatus of claim 11, whereinthe first web request comprises a hypertext transfer protocol (HTTP)request.
 13. The apparatus of claim 11, wherein the instructions, whenexecuted by the one or more processors, cause the apparatus to determinethe updated exponential moving average based on a formula,A_(U)=(R−A_(C))×C+A_(C), and wherein A_(U) is the updated exponentialmoving average, R is the response time, A_(C) is the exponential movingaverage of the plurality of past response times, and C is a smoothingconstant.
 14. The apparatus of claim 13, wherein the smoothing constantis based on a formula, C=2÷(N+1), and wherein Nis a weight value. 15.The apparatus of claim 11, wherein the instructions, when executed bythe one or more processors, cause the apparatus to determine whether toallow the first web request by performing at least one of: determiningto allow the first web request based on a formula, A_(C)+(A_(C)×C)>T,being satisfied, wherein A_(C) is the exponential moving average of theplurality of past response times, C is a smoothing constant, and T is atimeout value, or determining to disallow the first web request based onthe formula being not satisfied.
 16. A non-transitory computer-readablemedium storing instructions that, when executed, cause: receiving, froma web client, a first web request; determining, based on an exponentialmoving average of a plurality of past response times, whether to allowthe first web request; sending, based on the determination, the firstweb request to a server; receiving, from the server, a response to thefirst web request; determining a response time associated with theresponse; determining, based on the response time and the exponentialmoving average of the plurality of past response times, an updatedexponential moving average; and sending the response to the web client.17. The non-transitory computer-readable medium of claim 16, wherein thefirst web request comprises a hypertext transfer protocol (HTTP)request.
 18. The non-transitory computer-readable medium of claim 16,when executed, cause the determining the updated exponential movingaverage based on a formula, A_(U)=(R−A_(C))×C+A_(C), and wherein A_(U)is the updated exponential moving average, R is the response time, A_(C)is the exponential moving average of the plurality of past responsetimes, and C is a smoothing constant.
 19. The non-transitorycomputer-readable medium of claim 18, wherein the smoothing constant isbased on a formula, C=2÷(N+1), and wherein N is a weight value.
 20. Thenon-transitory computer-readable medium of claim 16, wherein theinstructions, when executed, cause the determining whether to allow thefirst web request by performing at least one of: determining to allowthe first web request based on a formula, A_(C)+(A_(C)×C)>T, beingsatisfied, wherein A_(C) is the exponential moving average of theplurality of past response times, C is a smoothing constant, and Tis atimeout value, or determining to disallow the first web request based onthe formula being not satisfied.